1. Field of the Invention
The invention relates to fungal endophytes of host plants, such as grass plants. In particular, the invention relates to prairie grass endophytes and combinations of these endophytes with agronomically elite grass plants.
2. Description of the Related Art
Endophytes are fungal or bacterial organisms that live within plants. Fungal endophytes, such as mycorrhiza, survive within various host plant tissues, often colonizing the intercellular spaces of host leaves, stems, flowers or roots. The symbiotic endophyte-host relationships can provide several fitness benefits to the host plant, such as enhancement of nutrition, increased drought tolerance and/or chemical defense from potential herbivores and often enhanced biomass production. Root-colonizing mycorrhizae survive on photosynthetic carbohydrates from the plant, and in return, aid in the solublization and uptake of water and minerals to the host, which can lead to the promotion of seed germination and plant growth. Additionally, the association of a fungal endophyte with a host plant often provides protection from pathogens or tolerance to a variety of biotic and abiotic stresses, such as insect infestation, grazing, water or nutrient deficiency, heat stress, salt or aluminum toxicity, and freezing temperatures. Host growth and fitness promotion and protection are thought to be achieved through multiple beneficial properties of the endophyte-host association. For instance, the endophytic organisms may produce growth-regulating substances to induce biomass production and alkaloids or other metabolites that have anti-insect and anti-herbivore properties. Additionally, fungal endophytes may directly suppress or compete with disease-causing microbes, protecting the plant from potential pathogens.